The present application is a divisional of U.S. application Ser. No. 11/699,693, filed Jan. 30, 2007 now abandoned, the entire contents of which are incorporated herein by reference.
The present invention is directed to vegetable oil derivatives. More particularly, the present invention is directed to functionalized vegetable oil derivative macromonomers that can be used in latexes and coatings.
A key problem encountered by coatings manufacturers is the development of coating formulations with low volatile organic compound (VOC) content. For instance, emulsion polymers are currently formulated with coalescing aids or plasticizers in order to form films at and below ambient conditions yet dry to films of sufficient glass transition temperature (Tg) to perform adequately at and above room temperature. However, the coalescing aids evaporate upon application and constitute VOCs. In general, the ability of emulsion polymers to form or coalesce into a smooth film is governed by the minimum film temperature (MFT) of the polymer in question. Low MFT polymers are required in order to exhibit coalescence, flow, and surface wetting properties. However, if the polymer remains soft and tacky, the coatings are not usable. Therefore, it is necessary to develop a technology in which coating formulations contain suitable ingredients to provide an initial low MFT, which, upon application, form non-tacky, durable, hard, and water resistant surfaces having a Tg significantly above their MFT.
Various coating compositions which cure under ambient conditions are known in the prior art. A few such examples involve curing by a chemical reaction such as epoxide-carboxylic acid reaction, isocyanate-moisture reaction, polyaziridine-carboxylic acid reaction, and activated methylene-unsaturated acrylic reaction.
Recently, a number of new latex or emulsion compositions derived from semi-drying and/or non-drying oils have been developed for use in coatings, adhesives and inks. Such compositions are disclosed in U.S. Pat. Nos. 6,001,913; 6,174,948; and 6,203,720 each of which is incorporated herein by reference in its entirety. The inherent hydrophobicity of vegetable oil macromonomers (VOMMs) limits their ability to migrate through the aqueous phase during emulsion polymerization and results in less than random copolymerizability. The VOMMs are likely to remain in the monomer droplets unlike the smaller less hydrophobic comonomers that diffuse through the aqueous phase and randomly polymerize within particles. Eventually, the unpolymerized VOMM droplets coalesce and form a separate phase as they are incompatible with the water and latex particles. It would therefore be an advancement to develop VOMMs with more hydrophilicity to facilitate/promote VOMM diffusion through the aqueous phase. Moreover, long-term storage stability of monomers and polymers is decreased when monomers are synthesized with glycerol esters as esters are susceptible to hydrolysis. It would thus be an additional benefit to synthesize the monomers in the absence of glycerol ester groups to increase long term stability for monomers and polymers.
The search for additional compositions that can be used in latexes and coatings is continuing. Accordingly, it would be an advancement in the art to provide glycerol ester-free compositions made from renewable resources that are suitable for use in latexes and coatings.